men lose their masculinity (the social reward for correctly performed manhood) through advocating for, sympathizing with, or doing labor that is allocated to women.
(and I'm not talking about some innate, spiritual, or psychological masculinity. I mean social masculinity--being regarded by higher ranking men as masculine.)
you genuinely do lose your current standing if you meaningfully and consistently object to the economic, legal, and interpersonal status of women, especially in ways that implicate men around you.
many men believe that if they are willing to do this, occasionally, then they are owed a recuperation of their masculinity through some other means.
if they are sacrificing masculinity through advocating for women politically, then they expect to bolster their masculinity through receiving expressions of gratitude and adoration by women ("feminist men are so hot" "consent is sexy" "pro-choice men get laid more" etc.) or they expect to bolster their masculinity through emasculating other men by asserting the standards of masculinity they adhere to are the "real" masculinity ("real men support women" "sexists are immature boys, I'm a man" "I'm secure in my masculinity and they're insecure" etc.)
to dismantle patriarchy, you need to be able to advocate for women even when it means losing gendered status. other men mostly will not respect you, and many misogynist women will not respect you either. it might not get you laid or praised or validated. in fact, it will probably subject you to increased scrutiny and criticism (because feminized subjects are always subject to such, and if you lose social masculinity, you too will experience this to some degree).
will you still advocate for women even if there is no social benefit and only social cost? do you have principles, or do you just want the fantasy of being a benevolent ruler?